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Discussion Starter #1
The left cylinder won't fire up.
Thanks in advance!!! Your insights are much appreciated.

The Bike:
‘79 CX500 Custom
Bobbed about 10 years ago (hard-tailed, pods, etc).

The Condition:
  • Sitting for 5 years
  • New battery
  • Plugs were new when parked 5 years ago
  • Ignition switch is new
  • Cleaned carbs; replaced air cutoff valves & jetted to 20,90 (due to pods).
The Details:
  • Left side not firing
  • Starter spray; Left side still won't fire up, or sound like it's trying.
  • Right side starts quickly, idles, drives (with very little power).
  • I have spark on both sides, tried switching plugs and coils; no change
  • Left side has powerful air blowing when I run it without the spark plug (I don’t have compression test tools).
  • Exhaust on right side is hot, left side is not.
Next Steps?
Go back into the carbs?! The only thing I can think of is that I didn’t touch the idle jet under the main jet; the heads were stripped on both sides.
Question: Is there another jet under the rubber plug? I don’t think mine has this?
 

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Oh, and the idle jet under the rubber plug is pressed in in most of the CX carbs rather than being threaded. It’s under the rubber plug.

The stripped bit you’re talking about looks to be the emulsion tube under one of the main jets.

In the pic - have you removed the other rubber plug and jets? Should be two threaded jets total and one rubber plug per carb.

See the jets/emulsion tubes described here:

https://motofaction.org/motorcycles/honda-cx-gl/a-how-remove-carb-main-jets-emulsion-tube-needle-jet-cx500-gl500-cx650-gl650/
 

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do you have the main jets and rubber plug removed for the left carb picture or are the parts missing?

have you ever done the stator or cdi test?

oops i just saw the serial connector for your ignitec

butthe stator test is still valid as you could have a weak pickup coil
 

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Discussion Starter #5
Nope, I was spraying through the carbs. I'll give that a try next!!
Pictures are from various stages of disassembly, it's all back together now.
Never done a Stator test, I think I just found that link on the forum. I'll need to borrow a meter from my brother in law.
 

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Discussion Starter #7
Update: Removing the balance screw and spraying starter fluid had no noticeable difference.

I'm going to do the Stator test and report back, per JC's link and Murrayf's suggestion.
 

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From the looks of the filth in the carb jets, you need to properly clean out the carbs. It is not just what you can see with the bowls removed, but more importantly what you can't see. I see lots of scale and crud in both carb photos. If you are unable to remove any jets the most affordable solution is to strip and boil the carbs individually for 20-30 minutes. Then try to remove stuck jets if possible. If not, chase every passage possible with carb spray and compressed air. Whatever you spray in, should have an exit hole, somewhere. You may have to boil a badly tarnished carb more than once.
 

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Discussion Starter #9
Results of the stator test, what should I do next? Does this mean I need to open the engine? Not sure I'm up for that.

Key: 1--. means the reading had a 1 then two blank spaces then a decimal point.

1/5: 118.8
2/5: 98.4
3/5: 1--.
4/5: 116.1
6/5: 101.2
7/5: 1--.
9/8: 89.3
A/B: 1.6
B/C: 1.8
C/A: 1.8
9/5: 1--.

New, here, wasn't sure if I should add to this old thread or start a new one...
 

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Discussion Starter #11
Good catch! My first time using a meter, it was still on 200. Updated results below.

It looks like 9/5 is the issue? per Motofaction.org's website this is the 'Source Coil, Low speed.'

Is this why the left side won't fire up?
Sounds like I need a new stator, a new CDI or an Ignetech? Any other option?
Please let me know what this means and what you would advise for next steps to get things running.

New results on 2K
1/5: 116
2/5: 96
3/5: 214
4/5: 114
6/5: 98
7/5: 217
9/5: 356
9/8: 87
A/B: 000
B/C: 000
C/A: 000
 
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